Mechanical illustrator of the eye



v Nov. 17, 1931. H. WITT MECHANICAL ILLUSTRATOR OF THE EYE Filed Aug. 21. 1928 l atented Nov. 17, 1931 unrrso stares HERMANN WITT, OF MARNE, GERMANY MECHANICAL ILLUSTRATOR OF TIE-IE EYE Application filed August 21, 1928, Serial No. 301,046, and in Germany September 6, 1927.

This invention relates to improvements in mechanical illustrators of the eye, the object of the invention being to provide an improved apparatus of this class which is simple in construction, and by means of which the various states of the eye and their optical effects may be accurately demonstrated.

lVith the above and other objects in vi w, the invention consists in the construction, combination and arrangement of devices hereinafter described and claimed.

In the accompanying drawings Figure 1 is a plan of apparatus constructed and arranged in accordancewith this invention.

Figure 2 is a similar view of the operating mechanism with the frame, plate and cardboard removed.

In the embodiment of my invention l provide a board 1 which may be of cardboard and is here shown as provided with a frame 2. The board may be covered by a sheet of glass. On the front side of the board is arranged a curved wire 9 to represent the outline of an eyeball, the ends of said wire being pivotally attached to fixed pivots 10, 11 which project from the board. On the rear side of the board are a pair of angle levers 22, 23 which have fixed pivots 20, 21 respectively. One arm of the lever 23 is sufiiciently long to project beyond one end of the board, so that said lever may be turned by the fingers. Said lever 23 has near the free end of its shorter arm a pin 25 which operates in a slot 24: in the overlapping end of the corresponding arm of the lever 22. Said levers 22, 23 are provided with eyelets. 26, 27 which project from said levers and through segmental slots 27 with which the board is provided and the opposite side portions of the wire 9 pass freely through said eyelets.

()n the rear side of the board at the same end thereof as the levers 22, 23 is a lever 29: which may also be turned by the fingers and Said levers are connected relinks being at opposite sides of and spaced equidistant from the fixed pivot .29 of the lever 29. Hence the levers 32, 33 may be simultaneously turned in opposite directions by slightly moving the free end of the lever 29,. as will be understood. Said levers 32, 33 are respectively provided at their free ends .with attaching pins or studs 14, 15 to which the opposite ends of oppositely curved wires 12, 13 are attached, said wires having their concave sides opposed and being arranged in the space between the ends of the eyeball indicating wire 9.

The attaching pins 14, 15 pass through suit-able small openings with which the board is provided. Said wires 12, 13 indicate the crystalline lens, and it will be understood that by appropriately turning the lever 29 their connected ends may be moved toward in dotted lines in Figure 1. When the points 26, 27 of 22, 23 move the sides of the wire toward each other so as to dispose the said wire in the form of an ellipse with a hori- Zontal axis, which is done by moving the free end of the lever 23 upwardly, said wire 9 then represents a short-sighted eyeball. When said lever is turned in the opposite direction to cause the opposite sides ofthe wire 9 to be moved from each other and thereby cause said wire to assume the form of an ellipse having its axis vertical, said Wire then indicates a form of an over or far sighted eyeball as will be understood. The lever 23 has a pointer 28 which plays on a scale graduated as normal, near sighted and far sighted, as shown in Figure 1.

Ray demonstrating wires 5, 6 which are normally parallel as indicated in full lines in Figure 1, have their inner ends mounted 1 g. all

on the fixed pivots 3, 4 which are near the upper and lower sides of the crystalline lens indicated by the wires 12, 13 and rearwardly converging ray indicating wires 7, 8 extend from the inner ends of the wires 5, 6 and in effect to 111 continuations thereof, said wires 7, 8 intersecting at a point which coincides with the center of the retina. A T-shapcd lever 17 is mounted near the lower side of the board on the rear side thereof on a fixed pivot 16 and its horizontal arms are pivotally connected to wires 18, 19" which wires are respectircly provided with eyelets 18, 19, which eyelets operate in curved slots 19 with which the board is provided and the said wires 5, 6 respectively pass through the eyelets 18, 19.

It ill be understood that by turning the lever 1" by the fingers, wires 5, 6 may be arranged in normal, horizontal relation to corrcsgond with a normal eyeball, as indi- 'ated by the full line position of the wire 9 and to cause the point of intersection of the wires 7, 8 to be coincident with the center of the retina. Said point of intersection may be shifted to correspond with the center of the retina when the wire is arranged in either of the two dotted line positions, as will be understood, it being essential in order to effeet a correct demonstration, that the point intersection of the wires 7, 8 be always coincident with the center of the retina, no matter in what form the wire 9 is arranged.

By appropriately operating the three levers 17, 23 and 29 all variations of the state and optical qualities of the normal, shortsighted, over sighted and old sighted eye can be demonstrated.

The moving mechanism for the second me chanical apparatus which demonstrates, when seeing with both eyes, the accommodation in connection with the convergence of the directions of view, and at the same time the squinling and its most common cause, is as follows.

Two plates 34 and 35, each having the shape of an eyeball, can be turned round the turning points of the eyes on pivots 36 or 37 respectively. The front and rear surfaces of the crystalline lens are likewise formed by wires 12 and 13, as is true of the before mentioned apparatus, which are fixed on plugs 14 and 15 movable toward and from each other. In the optical axis of the eyeballs and 35, somewhat before the retina, are plugs 38, which pass through slots 39 of the plate 1, and are flexibly connected with the upper vertex of a knee lever mechanism 40. On a connecting rod 41 vertically directed towards the optical axis of the eye, which can be placed immovable when both axes of the eye are in parallel direction, are guiding levers 42 and 4-3 for the knee lever mechanism 40, which by means of a rod 44 are connected with each other so that at the turning direction indicated by an arrow of a Wheel 45 on the end of a connecting rod 41, which is connected by shaft 46 with the free end of the right hand guiding lever 43, the plates 34 and 35 are so turned around the eye turning points 36 and 37 that the optical axes are caused to converge. The slots 39 permit the movement of the plugs 38 with the eyeball plates, as will be understood. The convexity of wires 12 and 13 may be increased by moving the plugs 14 and 15 toward each other. By turning the wheel 45 in a contrary direction the optical axes are caused to diverge. By pushing in or pulling out the connecting rod 41, the plates 34 and 35 may be correspondingly turned.

.Vhile I have herein shown and described one embodiment of the invention, 1 would have it understood that changes may be made in the form, proportion and construction of the several parts without departing from the spirit of the invention and within the scope of the appended claim.

What I claim is:

A plate, an eyeball outline wire having its ends spaced apartand attached to pins on the plate, a pair of oppositely curved lens outline wi es arranged in the space between the ends of the eyeball outline wire and having their opposite end portions connected together, ray demonstrating wires, means to move opposite sides of the eyeball outline wire toward or from each other to vary the length of the optical axis, means to move the connected ends of the lens outline wires toward or from each other to vary the convexity thereof, and means to move the ray demonstrating wires toward and from each other.

In testimony whereof I atiix my signature.

HERMANN VYITT. 

